sedulous

adjective

1. diligent in application or attention; persevering; assiduous.
2. persistently or carefully maintained: sedulous flattery.

adjective

1. constant or persistent in use or attention; assiduous; diligent

adj.1530s, from Latin sedulus “attentive, painstaking, diligent, busy, zealous,” probably from sedulo (adv.) “sincerely, diligently,” from sedolo “without deception or guile,” from se- “without, apart” (see secret) + dolo, ablative of dolus “deception, guile,” cognate with Greek dolos “ruse, snare.” Related: Sedulously; sedulousness.